Coating casting machine



July 6, 1937. L. B CASE I 2,086,117

COATING CASTING MACHINE Filed-Dec. '24, 1955 2 Sheets-Shet 1 ATTORNEYJuly '6, 1937. L. 5, CASE 2,086,1'1 7 COATING CASTING MACHINE Filed Dec.24, 1955 2 Sheets-Sheet 2 I INVENTOR ,3; I ATTORNEY Patented July 6,1937- UNETED STATES PATENT OFFICE COATING CASTING MACHINE ApplicationDecember 24, 1935, Serial No. 55,947

10 Claims.

This invention relates to-coating machines and more particularly tomachines for casting a coating compound blended with high, medium or lowboiling solvents such as varnishes, lacquers and the like onto basematerials such as textiles, paper, metals, acetates and regeneratedcellulose. Aqueous mixtures may, however be used with the constructionshown.

In the casting of a coating on a quick evaporating solvents are usedcertain difliculties arise. Due to the quick evaporation of the solventsthe coatings become so tacky that the casting is extremely difficult todo. If it is necessary to stop the machine the lacquer forms a tackyridge on the roll which must be removed before coating can be resumed.Solvents must be added to take care of the evaporation and this additionof solvents varies the density of the coating preventing a uniform depthof coating throughout the web. This invention is particularly adapted tocasting a coating with quick evaporating solvents but can be used forother coatings.

One of the objects of this invention is to maintain a high saturationpoint of volatile sola vents in the air surrounding the coating rolls toprevent drying of the lacquer.

Another object of the invention is'to provide a coating machine whereinthe movement of the paper may be stopped without stopping the rotationof the coating rolls.

A further object of the invention is to provide means to vary the widthof application of lacquer.

on the web of paper. 7 3 Still another object of the invention is toprovide accurate adjustments between the rolls.

Referring to the drawings:

Figure 1 is a view in side elevation of a device embodying theprinciples of my invention as applied to a coating machine.

Figure 2 is a view in side elevation with parts broken off.

Figure 3 is a diagrammatic detail viewshowing the drive of the coatingand backing roll.- 4 Figure 4 is a diagrammatic view of a modified formof device.

In carrying out my invention, I cover a predetermined portion of afinished roll face to an even thickness and smoothness and then cast the50 coating so formed onto the base materials. In so doing, the relativesurface speeds of the rolls depend upon the body or fluidity of thecoating materials.

In my method and apparatus the coating after 55 being laid on the rollis flowed or transferred onto base where (Cl. 91-49) I the basematerialewithout any pressure being exerted on the coating material inthe transfer operation from the roll tothe base material. This transferoperation I define as casting the coating onto thematerial.

I provide the usual web of paper I from unwind roll 2 which passesaround the usual rubber backing roll 3. .Roll 3 holds the web of paper Iagainst the reverse transfer roll 4 on shaft 5. Reverse turning doctorroll 6 is on shaft I and is cleaned by doctor -8 in the usual manner.Beneath the reverse transfer roll 4 is a movable pan 9 which projects inbeyond the center of ,roll,

4 to collect any drip should the coatingrolls be stopped and the lacquerrun back from the dam between the rolls. Gates III are fitted to therolls and hold back the lacquer from the edge of the rolls. It thuspermits coating inside of the edge of the web when this is desired. Thetwo gates III are free to slide so that the distance therebetween may bevaried. The doctor 8 is slightly above the gates I 0 and a second doctorI I is below the gates and at the bottom thereof. Between the gates IIIis a scraper III engaging the roller 6 and conoperating with the gatesIII and doctor I I to confine lacquer scraped off roller 6. Doctor II isheavy and is fixed between the side frames of the coating head and doesnot fit tightly against roll 4 but is positioned sufficiently nearthereto so that if excess lacquer should be pumped into the nip it holdsthe lacquer up while the machine is running and prevents it running backdown the face of doctor roll 4. Doctor II is a tight spring.

doctor and cleans roll 4 and is positioned below doctor II. Thus the twogates I0 slide above doctor II on the face of doctor II and fit betweenrolls 4 and 6. Rolls 4 and 6 are pivoted at fulcrum I2, the whole headswinging about fulcrum I2 with a support at the lower end by block I3resting on eccentric I4. Worm I5 controls eccentric I4 through segmentgearI6 which is directly connectedto the eccentric. The eccentric I4 hasa handle I I and a lock I8. The adjustment therefore between roll 3 androll 4 is controlled by the micrometer adjustment I5, I6, and if a quickrelease is desired, the lock I8 is released and the handle pulled outraising roll 4 about one-quarter of an inch above roll 3 througheccentric I4. The movement of roll 4 stops all coating on the paper. Theimportant element is that the coating rolls are still rotating. If it isdesired to stop the paper this may be done by releasing clutch I9 whichdisengages the drive to roll 3 but continues the drive to rolls 4 and 6to prevent the drying up of the coating rolls.

air into the pool.

The drive is as follows:

The main drive from the motor (not shown) goes to pulley 20 which drivesshaft 2| through gear reducer 22 through coupling 23 to variable speedunit 24. The variable speed unit 24 drives through sprocket 25, chain26, sprocket 21, shaft 5, to coating roll 4. Shaft in turn through gears28, 29, drives doctor roll 6 through shaft 1. Gear reducer 22 throughclutch l9 and shaft 30 drives sprocket 3|, chain 32, and sprocket 33 onshaft 34 of roll 3. Thus it will be seen that I by throwing out clutch.l9 roll 3 is stopped which in turn stops the feed of the paper withoutstop-.

ping the coating rolls permitting them to run without drying on thesurface. The lacquer is pumped or allowed to flow by gravity into thenip between rolls 4 and 6 through pipe 40 at the approximate rate thatit is being used up. Any excess lacquer overflows to the outsidecontainer from pan 9.

I have found that one of the difficulties in connection with rollcoating, that is, the entrapment of air in the presence of coating canbe practically removed in connection with my invention. Where arelatively deep pool of coating material is maintained at the nip,frothing frequently occurs causing the entrapment of air due to theagitation created by the rotation of the rolls. A further cause for theentrapment of air is the emission of the coating into the pool directlyfrom the source of supply. Where a pipe is used for the conduction ofliquid with a free stream of the material to the pool, furtherentrapment occurs by the stream carrying the The apparatus hereindisclosed shows the delivery of the coating material in quantitiesequivalent, to the amount used for the coating thereby maintaining onlya very small amount of coating at the nip of the rolls and asthiscoating is freshly supplied as it is used the opportunity for theentrapment of air by the agitation of this coating by the rolls iseliminated. In addition, the coating is introduced through the bottomplate or apron of doctor H and allowed to run down the surface thereofthereby permitting any air in the coating to escape before it entersinto the nip and also permits the coating to spread uniformly across theplate thereby feeding it throughout the entire length of the nip. Inthis way, much smaller quantities of coating can be used than where thecoating is introduced directly into the stream. An accurate adjustmentbetween rolls 4 and 6 is obtained by a sliding wedge 36 between thesupporting bearings of shafts 5 and l. The unique movable head adaptsitself to a complete enclosure as shown in Figures 1 and 2 wherein theframe 31 houses most of the head with a face plate 38 secured to frame31 to close the front. Plate 38 is hinged at 39 to permit inspection andenable the operator to get at the rolls and doctors and make theadjustment with respect to the gates. By the complete enclosure of thecoating head a proper saturated atmosphere of solid volatiles can bemaintained thereby preventing the drying up of the coating. Thiscomplete enclosure is most desirable and cannot ordinarily be done withthe usual roll coating machine s.

In the modified form shown in Figure 4, the only difference lies in theenclosing of the head. In this form the doctors 8 and Il operatingbetween the rolls 6 and 4 cooperate with the gates l0, and a cover 38extending from the top of H to beyond the top of 8 enclose the fountainleaving only a. portion of roll 4 exposed which portion is practicallyclean of lacquer after contacting the paper on roll 3. However, withthis modification, the continuous rotation of the'coating rolls isessential.

It will thus be seen that in this machine accurate adjustment of coatingrolls may be effected, a quick release of the coating head may be hadwith stoppage of the movement of the ing may behad and the necessity ofadding solvents is largely dispensed with. 1

What I claim is: 1. In a roll coating machine, a roll for motivating aweb of material passed a coating roll,

a coating head including said coating roll, said head pivotallyconnected to said roll coating machine, means for rotating said coatingroll independently of said roll for motivating the web whereby saidcoating roll may be continuously rotated regardless of the cessation ofrotation of the roll for motivating the web.

2.,In a roll coating machine a backing roll, a coating head including acoating roll, said head pivotally connected to said roll coatingmachine, means for rotating said coating roll regardless of the positionof the head and coating roll and independently of said backing rollwhereby said coating roll may be continuously rotated during therotation of the backing roll and during the.

cessation from rotation of the backing roll.

3. In a roll coating machine for lacquer coating and the like, a backingroll, a coating head including a coating roll, means for maintaining anatmosphere saturated with volatile solvents about said coating rollwithin said head, means for rotating said coating roll independently ofthe rotation of said backing roll whereby said coating roll iscontinuously rotated regardless of the rotation of the backing roll.

4. In a roll coating machine for lacquer coating and the like, acoatinghead including a coating roll, said coating head movable as aunit toward and from the material being coated, means for maintaining anatmosphere saturated with volatile solvents about said coating roll 'atall times, means for continuously rotating the coating roll, means forindependently motivating the web and stopping same without affecting therotation of the coating roll. 5. In a roll coating machine, a backingand feeding roll for the material being coated, means for operating saidbacking and feeding roll, a coating roll, means for continuouslyrotating said coating roll reversely to the travel of the material beingcoated and independent of stoppage of said backing and feeding roll, adoctor roll rotating in the same direction as the coating roll, andmeans for maintaining an atmosphere saturated with solvents about therolls at the point of application of the coating to the material.

6. In a roll coating machine, a backing and feeding roll for-thematerial being coated, a coating roll rotating in the reverse directionat the point of contact to the travel of the material being coated, adoctor roll cooperating with the heavy fiat doctor at a predetermineddistance from the coating roll and cooperating therewith ,to hold colorin the nip between the coating and doctor rolls, and a second fiatdoctor for cleaning the coating roll.

7. In a roll coating machine, a backing and feed roll for the materialbeing coated, means for operating said backing and feeding roll, acoating roll, means for continuously rotating said coating rollreversely to the direction of travel of the material and independent ofstop-page of said backing and feeding roll, means for varying the speedof rotation of the coating roll, a doctor roll cooperating with thecoating roll, said coating and doctor roll being enclosed to maintain asaturated atmosphere of coating solvents about the rolls.

8. In a reverse turning roll coating machine,

a reverse turning coating roll, a doctor roll there-' for, auxiliarydoctors forsaid coating roll and said doctor roll, gates and coverscooperating with said-doctors to enclose the nip to maintain anatmosphere saturated with volatile solvents for the coating.

9. In a reverse turning roll coating machine, a reverse turning coatingroll, a doctor roll therefor, auxiliary doctors for said coating rolland said doctor roll, gates and covers cooperating with said doctors toenclose the nip to maintain an atmosphere saturated with volatilesolvents for the coating, and a variable speed drive for [said rolls.

10. In a roll coater, a coating roll, means for covering a predeterminedportion of said coating roll face with fluid material to an eventhickness and smoothness, an enclosure for said coating roll, means forliberating entrapped air from 'said material prior to covering saidpredetermined portion, means for casting said coating without anypre'ssurebeing used on the coating material from the roll to a basematerial, means for continuously rotating said coating roll independentof stoppage of said .base material and means for controlling the surfacespeed of the coating roll in accordance with the fluidity of the coatingmaterial.

LYNN is. cAsE.

